Although the cost is less, "it demonstrates the lengths Bezos is willing to go to guard against real or perceived threats as his public profile grows," the report said. Amazon spends $1.6 million a year to protect its boss from external threats, the report added.

Apple spent about $310,000 on personal security services for CEO Tim Cook last year while Oracle spent over $1.6 million to protect CEO Larry Ellison.

Facebook, however, spent $20 million on its CEO Mark Zuckerberg's personal security last year -- four times more than what he received for security in 2016, owing to the growing privacy scandals the social networking giant is facing globally.

Gavin de Becker, a veteran security consultant at Amazon, wrote a first-person account in The Daily Beast last month, claiming that Saudi Arabia hacked Bezos' smartphone and allegedly shared personal information about his extramarital affair with a media outlet. The monarchy was "intent on harming Jeff Bezos" over The Washington Post (owned by Bezos) coverage of murdered journalist Jamal Khashoggi, wrote de Becker.

The private phone messages of Bezos sent to his lover, former TV anchor Lauren Sanchez, were published in The National Enquirer in October. Saudi journalist Khashoggi was murdered at the Saudi consulate in Turkey's Istanbul in October 2018. Saudi Arabia has denied involvement in the Bezos affair.